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Cao N, Cai W, Qian L, Nie Z, Mao C, Cui S. Emulating Titin by a Multidomain DNA Structure. ACS Macro Lett 2023; 12:59-64. [PMID: 36573670 DOI: 10.1021/acsmacrolett.2c00585] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Titin, a giant protein containing multiple tandem domains, is essential in maintaining the superior mechanical performance of muscle. The consecutive and reversible unfolding and refolding of the domains are crucial for titin to serve as a modular spring. Since the discovery of the mechanical features of a single titin molecule, the exploration of biomimetic materials with titin-emulating modular structures has been an active field. However, it remains a challenge to prepare these modular polymers on a large scale due to the complex synthesis process. In this study, we propose modular DNA with multiple hairpins (MH-DNA) as the fundamental block for the bottom-up design of advanced materials. By analyzing the unfolding and refolding dynamics of modular hairpins by atomic force microscopy (AFM)-based single-molecule force spectroscopy (SMFS), we find that MH-DNA shows comparable stability to those of polyproteins like titin. The unique low hysteresis of modular hairpin makes it an ideal molecular spring with remarkable mechanical efficiency. On the basis of the well-established DNA synthesis techniques, we anticipate that MH-DNA can be used as a promising building block for advanced materials with a combination of superior structural stability, considerable extensibility, and high mechanical efficiency.
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Affiliation(s)
- Nanpu Cao
- College of Chemistry, Key Laboratory of Advanced Technologies of Materials (Ministry of Education), Southwest Jiaotong University, Chengdu 610031, China
| | - Wanhao Cai
- College of Chemistry, Key Laboratory of Advanced Technologies of Materials (Ministry of Education), Southwest Jiaotong University, Chengdu 610031, China
| | - Lu Qian
- College of Chemistry, Key Laboratory of Advanced Technologies of Materials (Ministry of Education), Southwest Jiaotong University, Chengdu 610031, China
| | - Zhou Nie
- State Key Laboratory of Chemo/Bio-Sensing and Chemometrics, College of Chemistry and Chemical Engineering, Hunan University, Changsha 410082, China
| | - Chengde Mao
- Department of Chemistry, Purdue University, West Lafayette, Indiana 47907, United States
| | - Shuxun Cui
- College of Chemistry, Key Laboratory of Advanced Technologies of Materials (Ministry of Education), Southwest Jiaotong University, Chengdu 610031, China
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52
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Qian L, Zhang K, Guo X, Yu M. What happens when chitin becomes chitosan? A single-molecule study. RSC Adv 2023; 13:2294-2300. [PMID: 36741137 PMCID: PMC9841443 DOI: 10.1039/d2ra07303j] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2022] [Accepted: 01/09/2023] [Indexed: 01/19/2023] Open
Abstract
Chitin and chitosan are important support structures for many organisms and are important renewable macromolecular biomass resources. Structurally, with the removal of acetyl group, the solubility of chitosan is improved. However, the specific mechanism of solubility enhancement from chitin to chitosan is still unclear. In this study, the atomic force microscopy (AFM)-based single molecule force spectroscopy (SMFS) was used to obtain the single-chain mechanical behavior of chitin and chitosan. The results show that the hydrogen (H)-bonds' state, which can be influenced by the solvent, determines the degree of binding water (solubility) of polysaccharides, and that the binding water energy of a single chitosan chain is 6 times higher than that of chitin in water. Thus, H-bonding is the key to solubility enhancement and can be used to modulate the solubility properties of chitosan. It is expected that our studies can help to understand the structural and functional properties of chitin and chitosan at the single molecule level.
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Affiliation(s)
- Lu Qian
- School of Materials Science and Engineering, South China University of TechnologyGuangzhou 510641China
| | - Kai Zhang
- School of Mechanical Engineering, Sichuan UniversityChengdu 610065China
| | - Xin Guo
- School of Mechanical Engineering, Sichuan UniversityChengdu 610065China
| | - Miao Yu
- School of Mechanical Engineering, Sichuan UniversityChengdu 610065China
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53
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Melo MCR, Gomes DEB, Bernardi RC. Molecular Origins of Force-Dependent Protein Complex Stabilization during Bacterial Infections. J Am Chem Soc 2023; 145:70-77. [PMID: 36455202 DOI: 10.1021/jacs.2c07674] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/05/2022]
Abstract
The unbinding pathway of a protein complex can vary significantly depending on biochemical and mechanical factors. Under mechanical stress, a complex may dissociate through a mechanism different from that used in simple thermal dissociation, leading to different dissociation rates under shear force and thermal dissociation. This is a well-known phenomenon studied in biomechanics whose molecular and atomic details are still elusive. A particularly interesting case is the complex formed by bacterial adhesins with their human peptide target. These protein interactions have a force resilience equivalent to those of covalent bonds, an order of magnitude stronger than the widely used streptavidin:biotin complex, while having an ordinary affinity, much lower than that of streptavidin:biotin. Here, in an in silico single-molecule force spectroscopy approach, we use molecular dynamics simulations to investigate the dissociation mechanism of adhesin/peptide complexes. We show how the Staphylococcus epidermidis adhesin SdrG uses a catch-bond mechanism to increase complex stability with increasing mechanical stress. While allowing for thermal dissociation in a low-force regime, an entirely different mechanical dissociation path emerges in a high-force regime, revealing an intricate mechanism that does not depend on the peptide's amino acid sequence. Using a dynamic network analysis approach, we identified key amino acid contacts that describe the mechanics of this complex, revealing differences in dynamics that hinder thermal dissociation and establish the mechanical dissociation path. We then validate the information content of the selected amino acid contacts using their dynamics to successfully predict the rupture forces for this complex through a machine learning model.
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Affiliation(s)
- Marcelo C R Melo
- Department of Physics, Auburn University, Auburn, Alabama 36849, United States
| | - Diego E B Gomes
- Department of Physics, Auburn University, Auburn, Alabama 36849, United States
| | - Rafael C Bernardi
- Department of Physics, Auburn University, Auburn, Alabama 36849, United States
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54
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Hou R, Wang Z. Extract Motive Energy from Single-Molecule Trajectories. J Phys Chem B 2022; 126:10460-10470. [PMID: 36459483 DOI: 10.1021/acs.jpcb.2c06802] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/05/2022]
Abstract
Single-molecule trajectories from nonequilibrium unfolding experiments are widely used to recover a biomolecule's intrinsic free-energy profile. Trajectories of molecular motors from similar single-molecule experiments may be mapped to biased diffusion over an inclined free-energy profile. Such an effective potential is not a static equilibrium property anymore, and how it can benefit molecular motor study is unclear. Here, we introduce a method to deduce this effective potential from motor trajectories with realistic temporal-spatial resolution and find that the potential yields a motor's stall force─a quantity that not only characterizes a motor's force-generating capacity but also largely determines its energy efficiency. Interestingly, this potential allows the extraction of a motor's stall force from trajectories recorded at a single resisting force or even zero force, as verified with trajectories from two molecular motor models and also experimental trajectories from a real artificial motor. This finding drastically reduces the difficulty of stall force measurement, making it accessible even to force-incapable optical tracking experiments (commonly regarded as irrelevant to stall force determination). This study further provides a method for experimentally measuring a second-law-decreed least energy price for submicroscopic directionality─a previously elusive but thermodynamically important quantity pertinent to efficient energy conversion of molecular motors.
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Affiliation(s)
- Ruizheng Hou
- Department of Applied Physics, School of Science, Xi'an University of Technology, Xi'an, Shaan Xi710048, China
| | - Zhisong Wang
- Department of Physics and NUS Graduate School for Integrative Sciences and Engineering, National University of Singapore, Singapore117542, Singapore
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55
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Wang C, Chantraine C, Viljoen A, Herr AB, Fey PD, Horswill AR, Mathelié-Guinlet M, Dufrêne YF. The staphylococcal biofilm protein Aap mediates cell-cell adhesion through mechanically distinct homophilic and lectin interactions. PNAS NEXUS 2022; 1:pgac278. [PMID: 36712378 PMCID: PMC9802226 DOI: 10.1093/pnasnexus/pgac278] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/10/2022] [Accepted: 12/01/2022] [Indexed: 12/04/2022]
Abstract
The accumulation phase of staphylococcal biofilms relies on both the production of an extracellular polysaccharide matrix and the expression of bacterial surface proteins. A prototypical example of such adhesive proteins is the long multidomain protein Aap (accumulation-associated protein) from Staphylococcus epidermidis, which mediates zinc-dependent homophilic interactions between Aap B-repeat regions through molecular forces that have not been investigated yet. Here, we unravel the remarkable mechanical strength of single Aap-Aap homophilic bonds between living bacteria and we demonstrate that intercellular adhesion also involves sugar binding through the lectin domain of the Aap A region. We find that the mechanical force needed to unfold individual β-sheet-rich G5-E domains from the Aap B-repeat regions is very high, ranging from 300 up to 1,000 pN at high loading rates, indicating these are extremely stable. This high mechanostability provides a means to the cells to form highly adhesive and cohesive biofilms capable of sustaining high physiological shear stress. Importantly, we identify a previously undescribed role of Aap in bacterial-bacterial adhesion, that is, heterophilic sugar binding by a specific lectin domain located in the N-terminal A region, which might be important to establish initial contacts between cells before strong homophilic bonds come into play. This study emphasizes the remarkable mechanical and binding properties of Aap as well as its wide diversity of adhesive functions.
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Affiliation(s)
| | | | - Albertus Viljoen
- Louvain Institute of Biomolecular Science and Technology, UCLouvain, Croix du Sud, 4-5, bte L7.07.07, B-1348 Louvain-la-Neuve, Belgium
| | - Andrew B Herr
- Divisions of Immunobiology and Infectious Diseases, Cincinnati Children’s Hospital Medical Center, Cincinnati, OH 45229, USA
| | - Paul D Fey
- Department of Pathology and Microbiology, University of Nebraska Medical Center, Omaha, NE 68198, USA
| | - Alexander R Horswill
- Department of Immunology and Microbiology, University of Colorado School of Medicine, Aurora, CO 80045, USA
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56
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Kahle ER, Patel N, Sreenivasappa HB, Marcolongo MS, Han L. Targeting cell-matrix interface mechanobiology by integrating AFM with fluorescence microscopy. PROGRESS IN BIOPHYSICS AND MOLECULAR BIOLOGY 2022; 176:67-81. [PMID: 36055517 PMCID: PMC9691605 DOI: 10.1016/j.pbiomolbio.2022.08.005] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/08/2022] [Revised: 08/14/2022] [Accepted: 08/18/2022] [Indexed: 06/15/2023]
Abstract
Mechanosensing at the interface of a cell and its surrounding microenvironment is an essential driving force of physiological processes. Understanding molecular activities at the cell-matrix interface has the potential to provide novel targets for improving tissue regeneration and early disease intervention. In the past few decades, the advancement of atomic force microscopy (AFM) has offered a unique platform for probing mechanobiology at this crucial microdomain. In this review, we describe key advances under this topic through the use of an integrated system of AFM (as a biomechanical testing tool) with complementary immunofluorescence (IF) imaging (as an in situ navigation system). We first describe the body of work investigating the micromechanics of the pericellular matrix (PCM), the immediate cell micro-niche, in healthy, diseased, and genetically modified tissues, with a focus on articular cartilage. We then summarize the key findings in understanding cellular biomechanics and mechanotransduction, in which, molecular mechanisms governing transmembrane ion channel-mediated mechanosensing, cytoskeleton remodeling, and nucleus remodeling have been studied in various cell and tissue types. Lastly, we provide an overview of major technical advances that have enabled more in-depth studies of mechanobiology, including the integration of AFM with a side-view microscope, multiple optomicroscopy, a fluorescence recovery after photobleaching (FRAP) module, and a tensile stretching device. The innovations described here have contributed greatly to advancing the fundamental knowledge of extracellular matrix biomechanics and cell mechanobiology for improved understanding, detection, and intervention of various diseases.
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Affiliation(s)
- Elizabeth R Kahle
- School of Biomedical Engineering, Science and Health Systems, Drexel University, Philadelphia, PA 19104, United States
| | - Neil Patel
- School of Biomedical Engineering, Science and Health Systems, Drexel University, Philadelphia, PA 19104, United States
| | - Harini B Sreenivasappa
- Cell Imaging Center, Office of Research and Innovation, Drexel University, PA 19104, United States
| | - Michele S Marcolongo
- Department of Mechanical Engineering, Villanova University, Villanova, PA 19085, United States
| | - Lin Han
- School of Biomedical Engineering, Science and Health Systems, Drexel University, Philadelphia, PA 19104, United States.
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57
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Rief M, Žoldák G. Single-molecule mechanical studies of chaperones and their clients. BIOPHYSICS REVIEWS 2022; 3:041301. [PMID: 38505517 PMCID: PMC10903372 DOI: 10.1063/5.0098033] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/04/2022] [Accepted: 09/12/2022] [Indexed: 03/21/2024]
Abstract
Single-molecule force spectroscopy provides access to the mechanics of biomolecules. Recently, magnetic and laser optical tweezers were applied in the studies of chaperones and their interaction with protein clients. Various aspects of the chaperone-client interactions can be revealed based on the mechanical probing strategies. First, when a chaperone is probed under load, one can examine the inner workings of the chaperone while it interacts with and works on the client protein. Second, when protein clients are probed under load, the action of chaperones on folding clients can be studied in great detail. Such client folding studies have given direct access to observing actions of chaperones in real-time, like foldase, unfoldase, and holdase activity. In this review, we introduce the various single molecule mechanical techniques and summarize recent single molecule mechanical studies on heat shock proteins, chaperone-mediated folding on the ribosome, SNARE folding, and studies of chaperones involved in the folding of membrane proteins. An outlook on significant future developments is given.
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Affiliation(s)
- Matthias Rief
- Center for Functional Protein Assemblies (CPA), Physik Department, Technische Universität München, Ernst-Otto-Fischer-Str., 8, D-85748 Garching, Germany
| | - Gabriel Žoldák
- Center for Interdisciplinary Biosciences, Technology and Innovation Park, P. J. Šafárik University, Trieda SNP 1, 040 11 Košice, Slovakia
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58
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Galle MHJJ, Li J, Frantsuzov PA, Basché T, Scheblykin IG. Self-Healing Ability of Perovskites Observed via Photoluminescence Response on Nanoscale Local Forces and Mechanical Damage. ADVANCED SCIENCE (WEINHEIM, BADEN-WURTTEMBERG, GERMANY) 2022; 10:e2204393. [PMID: 36453591 PMCID: PMC9811431 DOI: 10.1002/advs.202204393] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/19/2022] [Revised: 10/18/2022] [Indexed: 06/17/2023]
Abstract
The photoluminescence (PL) of metal halide perovskites can recover after light or current-induced degradation. This self-healing ability is tested by acting mechanically on MAPbI3 polycrystalline microcrystals by an atomic force microscope tip (applying force, scratching, and cutting) while monitoring the PL. Although strain and crystal damage induce strong PL quenching, the initial balance between radiative and nonradiative processes in the microcrystals is restored within a few minutes. The stepwise quenching-recovery cycles induced by the mechanical action is interpreted as a modulation of the PL blinking behavior. This study proposes that the dynamic equilibrium between active and inactive states of the metastable nonradiative recombination centers causing blinking is perturbed by strain. Reversible stochastic transformation of several nonradiative centers per microcrystal under application/release of the local stress can lead to the observed PL quenching and recovery. Fitting the experimental PL trajectories by a phenomenological model based on viscoelasticity provides a characteristic time of strain relaxation in MAPbI3 on the order of 10-100 s. The key role of metastable defect states in nonradiative losses and in the self-healing properties of perovskites is suggested.
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Affiliation(s)
- Marco H. J. J. Galle
- Department of ChemistryJohannes Gutenberg‐UniversityDuesbergweg 10‐1455128MainzGermany
| | - Jun Li
- Chemical Physics and NanoLundLund UniversityBox 124Lund22100Sweden
| | - Pavel A. Frantsuzov
- Voevodsky Institute of Chemical Kinetics and CombustionSiberian Branch of the Russian Academy of ScienceInstitutskaya 3Novosibirsk630090Russia
| | - Thomas Basché
- Department of ChemistryJohannes Gutenberg‐UniversityDuesbergweg 10‐1455128MainzGermany
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59
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New insights into the effects of growth phase and enzymatic treatment on the cell-wall properties of Chlorella vulgaris microalgae. ALGAL RES 2022. [DOI: 10.1016/j.algal.2022.102955] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
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60
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Pokhrel P, Wang J, Selvam S, Jonchhe S, Mandal S, Mao H. Ensemble Force Spectroscopy of a G-Quadruplex Cluster on a Single-Molecule Platform. Biomacromolecules 2022; 23:4795-4803. [PMID: 36322676 PMCID: PMC10347895 DOI: 10.1021/acs.biomac.2c00959] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
Single-molecule methods offer high sensitivities with precisions superior to bulk assays. However, these methods are low in throughput and cannot repetitively interrogate the same cluster of molecular units. In this work, we investigate a tandem array of G-quadruplexes on a single-molecule DNA template with a throughput of at least two orders of magnitude higher than single-molecule force spectroscopy. During mechanical unfolding by optical tweezers, the array of G-quadruplexes experiences identical force, temperature, and ionic conditions, which not only reduce environmental noise but also render unfolding transitions indistinguishable among individual G-quadruplexes. The resultant ensemble behaviors are analyzed by scanning force diagrams, which reveals accurate F1/2 values, where 50% of G-quadruplexes are unfolded. Independent of the number of G-quadruplexes (n > 15) contained in a cluster, F1/2 can effectively evaluate G-quadruplex ligands in a new method called differential scanning forcemetry. When the same G-quadruplex cluster is subject to a series of constant forces in force-jump experiments, unfolding rate constants of G-quadruplexes can be effectively evaluated as a function of force. The high precision demonstrated in all of these measurements reflects the power of repetitive sampling on the same cluster of single-molecule entities under identical conditions. Since biomolecules such as DNA, RNA, and proteins can be conveniently incorporated in a tandem array, we anticipate that this ensemble assay on single-molecule entities (EASE) provides a generic means of ensemble force spectroscopy to amalgamate the accuracy of ensemble measurements with the precision of single-molecule methods.
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Affiliation(s)
| | | | - Sangeetha Selvam
- Department of Chemistry and Biochemistry, Kent State University, Kent, OH 44242, USA
| | - Sagun Jonchhe
- Department of Chemistry and Biochemistry, Kent State University, Kent, OH 44242, USA
| | - Shankar Mandal
- Department of Chemistry and Biochemistry, Kent State University, Kent, OH 44242, USA
| | - Hanbin Mao
- Department of Chemistry and Biochemistry, Kent State University, Kent, OH 44242, USA
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Chan FY, Kurosaki R, Ganser C, Takeda T, Uchihashi T. Tip-scan high-speed atomic force microscopy with a uniaxial substrate stretching device for studying dynamics of biomolecules under mechanical stress. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2022; 93:113703. [PMID: 36461522 DOI: 10.1063/5.0111017] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/18/2022] [Accepted: 10/09/2022] [Indexed: 06/17/2023]
Abstract
High-speed atomic force microscopy (HS-AFM) is a powerful tool for studying the dynamics of biomolecules in vitro because of its high temporal and spatial resolution. However, multi-functionalization, such as combination with complementary measurement methods, environment control, and large-scale mechanical manipulation of samples, is still a complex endeavor due to the inherent design and the compact sample scanning stage. Emerging tip-scan HS-AFM overcame this design hindrance and opened a door for additional functionalities. In this study, we designed a motor-driven stretching device to manipulate elastic substrates for HS-AFM imaging of biomolecules under controllable mechanical stimulation. To demonstrate the applicability of the substrate stretching device, we observed a microtubule buckling by straining the substrate and actin filaments linked by α-actinin on a curved surface. In addition, a BAR domain protein BIN1 that senses substrate curvature was observed while dynamically controlling the surface curvature. Our results clearly prove that large-scale mechanical manipulation can be coupled with nanometer-scale imaging to observe biophysical effects otherwise obscured.
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Affiliation(s)
- Feng-Yueh Chan
- Department of Physics, Nagoya University, Chikusa-ku, Nagoya 464-8602, Japan
| | - Ryo Kurosaki
- Department of Physics, Nagoya University, Chikusa-ku, Nagoya 464-8602, Japan
| | - Christian Ganser
- Exploratory Research Center on Life and Living Systems (ExCELLS), National Institutes of Natural Sciences, 5-1 Higashiyama, Myodaiji, Okazaki, Aichi 444-8787, Japan
| | - Tetsuya Takeda
- Faculty of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University, Kita-Ku, Okayama 700-8558, Japan
| | - Takayuki Uchihashi
- Department of Physics, Nagoya University, Chikusa-ku, Nagoya 464-8602, Japan
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62
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MA BO, KIM JINWOO, TUNG STEVE. Single DNA Translocation and Electrical Characterization Based on Atomic Force Microscopy and Nanoelectrodes. IEEE OPEN JOURNAL OF NANOTECHNOLOGY 2022; 3:124-130. [PMID: 37284032 PMCID: PMC10241429 DOI: 10.1109/ojnano.2022.3217108] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Precision DNA translocation control is critical for achieving high accuracy in single molecule-based DNA sequencing. In this report, we describe an atomic force microscopy (AFM) based method to linearize a double-stranded DNA strand during the translocation process and characterize the electrical properties of the moving DNA using a platinum (Pt) nanoelectrode gap. In this method, λDNAs were first deposited on a charged mica substrate surface and topographically scanned. A single DNA suitable for translocation was then identified and electrostatically attached to an AFM probe by pressing the probe tip down onto one end of the DNA strand without chemical functionalizations. Next, the DNA strand was lifted off the mica surface by the probe tip. The pulling force required to completely lift off the DNA agreed well with the theoretical DNA adhesion force to a charged mica surface. After liftoff, the captured DNA was translocated at varied speeds across the substrate and ultimately across the Pt nanoelectrode gap for electrical characterizations. Finally, finite element analysis of the effect of the translocating DNA on the conductivity of the nanoelectrode gap was conducted, validating the range of the gap current measured experimentally during the DNA translocation process.
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Affiliation(s)
- BO MA
- Department of Mechanical Engineering, University of Arkansas, Fayetteville, AR 72701 USA
| | - JIN-WOO KIM
- Department of Biological & Agricultural Engineering, University of Arkansas, Fayetteville, AR 72701 USA
- Materials Science and Engineering Program, University of Arkansas, Fayetteville, AR 72701 USA
- Institute for Nanoscience and Engineering, University of Arkansas, Fayetteville, AR 72701 USA
| | - STEVE TUNG
- Department of Mechanical Engineering, University of Arkansas, Fayetteville, AR 72701 USA
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63
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Suhail A, Banerjee A, Rajesh R. Kinetic model description of dissipation and recovery in collagen fibrils under cyclic loading. Phys Rev E 2022; 106:044407. [PMID: 36397482 DOI: 10.1103/physreve.106.044407] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2022] [Accepted: 09/26/2022] [Indexed: 06/16/2023]
Abstract
Collagen fibrils, when subjected to cyclic loading, are known to exhibit hysteretic behavior with energy dissipation that is partially recovered on relaxation. In this paper, we develop a kinetic model for a collagen fibril incorporating presence of hidden loops and stochastic fragmentation as well as reformation of sacrificial bonds. We show that the model reproduces well the characteristic features of reported experimental data on cyclic response of collagen fibrils, such as moving hysteresis loops, time evolution of residual strains and energy dissipation, recovery on relaxation, etc. We show that the approach to the steady state is controlled by a characteristic cycle number for both residual strain as well as energy dissipation and is in good agreement with reported existing experimental data.
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Affiliation(s)
- Amir Suhail
- The Institute of Mathematical Sciences, CIT Campus, Taramani, Chennai 600113, India
- Homi Bhabha National Institute, Training School Complex, Anushakti Nagar, Mumbai 400094, India
| | | | - R Rajesh
- The Institute of Mathematical Sciences, CIT Campus, Taramani, Chennai 600113, India
- Homi Bhabha National Institute, Training School Complex, Anushakti Nagar, Mumbai 400094, India
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64
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Lei H, Zhang J, Li Y, Wang X, Qin M, Wang W, Cao Y. Histidine-Specific Bioconjugation for Single-Molecule Force Spectroscopy. ACS NANO 2022; 16:15440-15449. [PMID: 35980082 DOI: 10.1021/acsnano.2c07298] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
Atomic force microscopy (AFM) based single-molecule force spectroscopy (SMFS) is a powerful tool to study the mechanical properties of proteins. In these experiments, site-specific immobilization of proteins is critical, as the tether determines the direction and amplitude of forces applied to the protein of interest. However, existing methods are mainly based on thiol chemistry or specific protein tags, which cannot meet the need of many challenging experiments. Here, we developed a histidine-specific phosphorylation strategy to covalently anchor proteins to an AFM cantilever tip or the substrate via their histidine tag or surface-exposed histidine residues. The formed covalent linkage was mechanically stable with rupture forces of over 1.3 nN. This protein immobilization method considerably improved the pickup rate and data quality of SMFS experiments. We further demonstrated the use of this method to explore the pulling-direction-dependent mechanical stability of green fluorescent protein and the unfolding of the membrane protein archaerhodopsin-3.
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Affiliation(s)
- Hai Lei
- Collaborative Innovation Center of Advanced Microstructures, National Laboratory of Solid State Microstructure, Department of Physics, Nanjing University 22 Hankou Road, Nanjing 210093, People's Republic of China
- Chemistry and Biomedicine Innovation Center (ChemBIC), Nanjing University 163 Xianlin Road, Nanjing 210023, People's Republic of China
| | - Junsheng Zhang
- Collaborative Innovation Center of Advanced Microstructures, National Laboratory of Solid State Microstructure, Department of Physics, Nanjing University 22 Hankou Road, Nanjing 210093, People's Republic of China
- Oujiang Laboratory (Zhejiang Lab for Regenerative Medicine, Vision and Brain Health), Wenzhou Institute, University of Chinese Academy of Sciences, Wenzhou 325001, People's Republic of China
| | - Ying Li
- Institute of Advanced Materials and Flexible Electronics (IAMFE), School of Chemistry and Materials Science, Nanjing University of Information Science & Technology 219 Ningliu Road, Nanjing, 210044, People's Republic of China
| | - Xin Wang
- Oujiang Laboratory (Zhejiang Lab for Regenerative Medicine, Vision and Brain Health), Wenzhou Institute, University of Chinese Academy of Sciences, Wenzhou 325001, People's Republic of China
| | - Meng Qin
- Collaborative Innovation Center of Advanced Microstructures, National Laboratory of Solid State Microstructure, Department of Physics, Nanjing University 22 Hankou Road, Nanjing 210093, People's Republic of China
| | - Wei Wang
- Collaborative Innovation Center of Advanced Microstructures, National Laboratory of Solid State Microstructure, Department of Physics, Nanjing University 22 Hankou Road, Nanjing 210093, People's Republic of China
| | - Yi Cao
- Collaborative Innovation Center of Advanced Microstructures, National Laboratory of Solid State Microstructure, Department of Physics, Nanjing University 22 Hankou Road, Nanjing 210093, People's Republic of China
- Chemistry and Biomedicine Innovation Center (ChemBIC), Nanjing University 163 Xianlin Road, Nanjing 210023, People's Republic of China
- Oujiang Laboratory (Zhejiang Lab for Regenerative Medicine, Vision and Brain Health), Wenzhou Institute, University of Chinese Academy of Sciences, Wenzhou 325001, People's Republic of China
- Jinan Microecological Biomedicine Shandong Laboratory, Jinan 250021, People's Republic of China
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65
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Knoff DS, Kim S, Fajardo Cortes KA, Rivera J, Cathey MVJ, Altamirano D, Camp C, Kim M. Non-Covalently Associated Streptavidin Multi-Arm Nanohubs Exhibit Mechanical and Thermal Stability in Cross-Linked Protein-Network Materials. Biomacromolecules 2022; 23:4130-4140. [PMID: 36149316 DOI: 10.1021/acs.biomac.2c00544] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Constructing protein-network materials that exhibit physicochemical and mechanical properties of individual protein constituents requires molecular cross-linkers with specificity and stability. A well-known example involves specific chemical fusion of a four-arm polyethylene glycol (tetra-PEG) to desired proteins with secondary cross-linkers. However, it is necessary to investigate tetra-PEG-like biomolecular cross-linkers that are genetically fused to the proteins, simplifying synthesis by removing additional conjugation and purification steps. Non-covalently, self-associating, streptavidin homotetramer is a viable, biomolecular alternative to tetra-PEG. Here, a multi-arm streptavidin design is characterized as a protein-network material platform using various secondary, biomolecular cross-linkers, such as high-affinity physical (i.e., non-covalent), transient physical, spontaneous chemical (i.e., covalent), or stimuli-induced chemical cross-linkers. Stimuli-induced, chemical cross-linkers fused to multi-arm streptavidin nanohubs provide sufficient diffusion prior to initiating permanent covalent bonds, allowing proper characterization of streptavidin nanohubs. Surprisingly, non-covalently associated streptavidin nanohubs exhibit extreme stability, which translates into material properties that resemble hydrogels formed by chemical bonds even at high temperatures. Therefore, this study not only establishes that the streptavidin nanohub is an ideal multi-arm biopolymer precursor but also provides valuable guidance for designing self-assembling nanostructured molecular networks that can properly harness the extraordinary properties of protein-based building blocks.
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Affiliation(s)
- David S Knoff
- Department of Biomedical Engineering, University of Arizona, Tucson, Arizona 85721, United States
| | - Samuel Kim
- Department of Biomedical Engineering, University of Arizona, Tucson, Arizona 85721, United States
| | - Kareen A Fajardo Cortes
- Department of Biomedical Engineering, University of Arizona, Tucson, Arizona 85721, United States
| | - Jocelyne Rivera
- Department of Biomedical Engineering, University of Arizona, Tucson, Arizona 85721, United States
| | - Marcus V J Cathey
- Department of Biomedical Engineering, University of Arizona, Tucson, Arizona 85721, United States
| | - Dallas Altamirano
- Department of Biomedical Engineering, University of Arizona, Tucson, Arizona 85721, United States
| | - Christopher Camp
- Department of Biomedical Engineering, University of Arizona, Tucson, Arizona 85721, United States
| | - Minkyu Kim
- Department of Biomedical Engineering, University of Arizona, Tucson, Arizona 85721, United States.,Department of Materials Science and Engineering, University of Arizona, Tucson, Arizona 85721, United States.,BIO5 Institute, University of Arizona, Tucson, Arizona 85719, United States
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66
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Buell AK. Stability matters, too - the thermodynamics of amyloid fibril formation. Chem Sci 2022; 13:10177-10192. [PMID: 36277637 PMCID: PMC9473512 DOI: 10.1039/d1sc06782f] [Citation(s) in RCA: 27] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2021] [Accepted: 01/30/2022] [Indexed: 12/26/2022] Open
Abstract
Amyloid fibrils are supramolecular homopolymers of proteins that play important roles in biological functions and disease. These objects have received an exponential increase in attention during the last few decades, due to their role in the aetiology of a range of severe disorders, most notably some of a neurodegenerative nature. While an overwhelming number of experimental studies exist that investigate how, and how fast, amyloid fibrils form and how their formation can be inhibited, a much more limited body of experimental work attempts to answer the question as to why these types of structures form (i.e. the thermodynamic driving force) and how stable they actually are. In this review, I attempt to give an overview of the types of experiments that have been performed to-date to answer these questions, and to summarise our current understanding of amyloid thermodynamics.
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Affiliation(s)
- Alexander K Buell
- Technical University of Denmark, Department of Biotechnology and Biomedicine Søltofts Plads, Building 227 2800 Kgs. Lyngby Denmark
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67
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Cheung E, Xia Y, Caporini MA, Gilmore JL. Tools shaping drug discovery and development. BIOPHYSICS REVIEWS 2022; 3:031301. [PMID: 38505278 PMCID: PMC10903431 DOI: 10.1063/5.0087583] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/07/2022] [Accepted: 06/21/2022] [Indexed: 03/21/2024]
Abstract
Spectroscopic, scattering, and imaging methods play an important role in advancing the study of pharmaceutical and biopharmaceutical therapies. The tools more familiar to scientists within industry and beyond, such as nuclear magnetic resonance and fluorescence spectroscopy, serve two functions: as simple high-throughput techniques for identification and purity analysis, and as potential tools for measuring dynamics and structures of complex biological systems, from proteins and nucleic acids to membranes and nanoparticle delivery systems. With the expansion of commercial small-angle x-ray scattering instruments into the laboratory setting and the accessibility of industrial researchers to small-angle neutron scattering facilities, scattering methods are now used more frequently in the industrial research setting, and probe-less time-resolved small-angle scattering experiments are now able to be conducted to truly probe the mechanism of reactions and the location of individual components in complex model or biological systems. The availability of atomic force microscopes in the past several decades enables measurements that are, in some ways, complementary to the spectroscopic techniques, and wholly orthogonal in others, such as those related to nanomechanics. As therapies have advanced from small molecules to protein biologics and now messenger RNA vaccines, the depth of biophysical knowledge must continue to serve in drug discovery and development to ensure quality of the drug, and the characterization toolbox must be opened up to adapt traditional spectroscopic methods and adopt new techniques for unraveling the complexities of the new modalities. The overview of the biophysical methods in this review is meant to showcase the uses of multiple techniques for different modalities and present recent applications for tackling particularly challenging situations in drug development that can be solved with the aid of fluorescence spectroscopy, nuclear magnetic resonance spectroscopy, atomic force microscopy, and small-angle scattering.
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Affiliation(s)
- Eugene Cheung
- Moderna, 200 Technology Square, Cambridge, Massachusetts 02139, USA
| | - Yan Xia
- Moderna, 200 Technology Square, Cambridge, Massachusetts 02139, USA
| | - Marc A. Caporini
- Moderna, 200 Technology Square, Cambridge, Massachusetts 02139, USA
| | - Jamie L. Gilmore
- Moderna, 200 Technology Square, Cambridge, Massachusetts 02139, USA
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68
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Leterrier C, Pullarkat PA. Mechanical role of the submembrane spectrin scaffold in red blood cells and neurons. J Cell Sci 2022; 135:276327. [PMID: 35972759 DOI: 10.1242/jcs.259356] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Spectrins are large, evolutionarily well-conserved proteins that form highly organized scaffolds on the inner surface of eukaryotic cells. Their organization in different cell types or cellular compartments helps cells withstand mechanical challenges with unique strategies depending on the cell type. This Review discusses our understanding of the mechanical properties of spectrins, their very distinct organization in red blood cells and neurons as two examples, and the contribution of the scaffolds they form to the mechanical properties of these cells.
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Affiliation(s)
- Christophe Leterrier
- Aix Marseille Université, CNRS, INP UMR 7051, NeuroCyto, Marseille 13005, France
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69
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The Development of Single Molecule Force Spectroscopy: From Polymer Biophysics to Molecular Machines. Q Rev Biophys 2022; 55:e9. [PMID: 35916314 DOI: 10.1017/s0033583522000087] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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70
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Jain M, Weber A, Maly K, Manjaly G, Deek J, Tsvyetkova O, Stulić M, Toca‐Herrera JL, Jantsch MF. A-to-I RNA editing of Filamin A regulates cellular adhesion, migration and mechanical properties. FEBS J 2022; 289:4580-4601. [PMID: 35124883 PMCID: PMC9546289 DOI: 10.1111/febs.16391] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2021] [Revised: 12/23/2021] [Accepted: 02/04/2022] [Indexed: 02/06/2023]
Abstract
A-to-I RNA editing by ADARs is an abundant epitranscriptomic RNA-modification in metazoa. In mammals, Flna pre-mRNA harbours a single conserved A-to-I RNA editing site that introduces a Q-to-R amino acid change in Ig repeat 22 of the encoded protein. Previously, we showed that FLNA editing regulates smooth muscle contraction in the cardiovascular system and affects cardiac health. The present study investigates how ADAR2-mediated A-to-I RNA editing of Flna affects actin crosslinking, cell mechanics, cellular adhesion and cell migration. Cellular assays and AFM measurements demonstrate that the edited version of FLNA increases cellular stiffness and adhesion but impairs cell migration in both, mouse fibroblasts and human tumour cells. In vitro, edited FLNA leads to increased actin crosslinking, forming actin gels of higher stress resistance. Our study shows that Flna RNA editing is a novel regulator of cytoskeletal organisation, affecting the mechanical property and mechanotransduction of cells.
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Affiliation(s)
- Mamta Jain
- Division of Cell BiologyCenter for Anatomy and Cell BiologyMedical University of ViennaAustria
| | - Andreas Weber
- Department of NanobiotechnologyInstitute for BiophysicsUniversity of Natural Resources and Life Sciences Vienna (BOKU)Austria
| | - Kathrin Maly
- Division of Cell BiologyCenter for Anatomy and Cell BiologyMedical University of ViennaAustria
| | - Greeshma Manjaly
- Division of Cell BiologyCenter for Anatomy and Cell BiologyMedical University of ViennaAustria
| | - Joanna Deek
- Department of Physics, Cellular Biophysics E27Technical University of MunichGarchingGermany
| | - Olena Tsvyetkova
- Division of Cell BiologyCenter for Anatomy and Cell BiologyMedical University of ViennaAustria
| | - Maja Stulić
- Division of Cell BiologyCenter for Anatomy and Cell BiologyMedical University of ViennaAustria
| | - José L. Toca‐Herrera
- Department of NanobiotechnologyInstitute for BiophysicsUniversity of Natural Resources and Life Sciences Vienna (BOKU)Austria
| | - Michael F. Jantsch
- Division of Cell BiologyCenter for Anatomy and Cell BiologyMedical University of ViennaAustria
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71
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Hughes MD, Cussons S, Mahmoudi N, Brockwell DJ, Dougan L. Tuning Protein Hydrogel Mechanics through Modulation of Nanoscale Unfolding and Entanglement in Postgelation Relaxation. ACS NANO 2022; 16:10667-10678. [PMID: 35731007 PMCID: PMC9331141 DOI: 10.1021/acsnano.2c02369] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Abstract
Globular folded proteins are versatile nanoscale building blocks to create biomaterials with mechanical robustness and inherent biological functionality due to their specific and well-defined folded structures. Modulating the nanoscale unfolding of protein building blocks during network formation (in situ protein unfolding) provides potent opportunities to control the protein network structure and mechanics. Here, we control protein unfolding during the formation of hydrogels constructed from chemically cross-linked maltose binding protein using ligand binding and the addition of cosolutes to modulate protein kinetic and thermodynamic stability. Bulk shear rheology characterizes the storage moduli of the bound and unbound protein hydrogels and reveals a correlation between network rigidity, characterized as an increase in the storage modulus, and protein thermodynamic stability. Furthermore, analysis of the network relaxation behavior identifies a crossover from an unfolding dominated regime to an entanglement dominated regime. Control of in situ protein unfolding and entanglement provides an important route to finely tune the architecture, mechanics, and dynamic relaxation of protein hydrogels. Such predictive control will be advantageous for future smart biomaterials for applications which require responsive and dynamic modulation of mechanical properties and biological function.
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Affiliation(s)
- Matt D.
G. Hughes
- School of
Physics and Astronomy, Faculty of Engineering and Physical Sciences, University of Leeds, Leeds LS2 9JT, U.K.
| | - Sophie Cussons
- Astbury Centre
for Structural Molecular Biology, University
of Leeds, Leeds LS2 9JT, U.K.
- School of
Molecular and Cellular Biology, Faculty of Biological Sciences, University of Leeds, Leeds LS2 9JT, U.K.
| | - Najet Mahmoudi
- ISIS
Neutron
and Muon Spallation Source, STFC Rutherford
Appleton Laboratory, Oxfordshire OX11 0QX, U.K.
| | - David J. Brockwell
- Astbury Centre
for Structural Molecular Biology, University
of Leeds, Leeds LS2 9JT, U.K.
- School of
Molecular and Cellular Biology, Faculty of Biological Sciences, University of Leeds, Leeds LS2 9JT, U.K.
| | - Lorna Dougan
- School of
Physics and Astronomy, Faculty of Engineering and Physical Sciences, University of Leeds, Leeds LS2 9JT, U.K.
- Astbury Centre
for Structural Molecular Biology, University
of Leeds, Leeds LS2 9JT, U.K.
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72
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Xia J, Zuo J, Li H. Molecular homogeneity of GB1 revealed by single molecule force spectroscopy. NANOSCALE 2022; 14:9925-9931. [PMID: 35788627 DOI: 10.1039/d2nr02614g] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
In single molecule studies, the ergodic hypothesis is inherently assumed, which states that the time average of a physical quantity of a single member of an ensemble is the same as the average of the same quantity on the whole ensemble at a given time. This hypothesis implies the homogeneity of a molecular ensemble of a system of interest. However, it is difficult to test the validity of the ergodic hypothesis experimentally. Recent theoretical work suggested that heterogeneity may be widely present in single molecule force spectroscopy studies. Here we used atomic force microscope based single molecule force spectroscopy to examine the molecular homogeneity/heterogeneity of a small globular protein GB1 in its mechanical unfolding reaction. Using a polyprotein (GB1)4, we directly measured the ensemble average and time average for a single molecule of the mechanical unfolding force and kinetic parameters that characterize the mechanical unfolding free energy profile of GB1. Our results showed that the ensemble averages of these physical quantities are indeed the same as the time averages for single molecules, and individual molecules did not show any differences amongst them in these physical quantities. These results are consistent with the expectation of the ergodic hypothesis and indicate that GB1 is a homogeneous molecular ensemble in its mechanical unfolding reaction on the time scale of our force spectroscopy experiments.
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Affiliation(s)
- Jiahao Xia
- Department of Chemistry, University of British Columbia, Vancouver, BC, V6T 1Z1, Canada.
| | - Jiacheng Zuo
- Department of Chemistry, University of British Columbia, Vancouver, BC, V6T 1Z1, Canada.
| | - Hongbin Li
- Department of Chemistry, University of British Columbia, Vancouver, BC, V6T 1Z1, Canada.
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73
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Stirnemann G. Molecular interpretation of single-molecule force spectroscopy experiments with computational approaches. Chem Commun (Camb) 2022; 58:7110-7119. [PMID: 35678696 DOI: 10.1039/d2cc01350a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Single molecule force-spectroscopy techniques have granted access to unprecedented molecular-scale details about biochemical and biological mechanisms. However, the interpretation of the experimental data is often challenging. Computational and simulation approaches (all-atom steered MD simulations in particular) are key to provide molecular details about the associated mechanisms, to help test different hypotheses and to predict experimental results. In this review, particular recent efforts directed towards the molecular interpretation of single-molecule force spectroscopy experiments on proteins and protein-related systems (often in close collaboration with experimental groups) will be presented. These results will be discussed in the broader context of the field, highlighting the recent achievements and the ongoing challenges for computational biophysicists and biochemists. In particular, I will focus on the input gained from molecular simulations approaches to rationalize the origin of the unfolded protein elasticity and the protein conformational behavior under force, to understand how force denaturation differs from chemical, thermal or shear unfolding, and to unravel the molecular details of unfolding events for a variety of systems. I will also discuss the use of models based on Langevin dynamics on a 1-D free-energy surface to understand the effect of protein segmentation on the work exerted by a force, or, at the other end of the spectrum of computational techniques, how quantum calculations can help to understand the reactivity of disulfide bridges exposed to force.
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Affiliation(s)
- Guillaume Stirnemann
- CNRS Laboratoire de Biochimie Théorique, Institut de Biologie Physico-Chimique, PSL University, Université de Paris, 13 rue Pierre et Marie Curie, 75005, Paris, France.
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74
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Liu Z, Thirumalai D. Cooperativity and Folding Kinetics in a Multidomain Protein with Interwoven Chain Topology. ACS CENTRAL SCIENCE 2022; 8:763-774. [PMID: 35756371 PMCID: PMC9228575 DOI: 10.1021/acscentsci.2c00140] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/07/2022] [Indexed: 06/15/2023]
Abstract
Although a large percentage of eukaryotic proteomes consist of proteins with multiple domains, not much is known about their assembly mechanism, especially those with intricate native state architectures. Some have a complex topology in which the structural elements along the sequence are interwoven in such a manner that the domains cannot be separated by cutting at any location along the sequence. Such proteins are multiply connected multidomain proteins (MMPs) with the three-domain (NMP, LID, and CORE) phosphotransferase enzyme adenylate kinase (ADK) being an example. We devised a coarse-grained model to simulate ADK folding initiated by changing either the temperature or guanidinium chloride (GdmCl) concentration. The simulations reproduce the experimentally measured melting temperatures (associated with two equilibrium transitions), FRET efficiency as a function of GdmCl concentration, and the folding times quantitatively. Although the NMP domain orders independently, cooperative interactions between the LID and the CORE domains are required for complete assembly of the enzyme. Kinetic simulations show that, on the collapse time scale, multiple interconnected metastable states are populated, attesting to the folding heterogeneity. The network of kinetically connected states reveals that the CORE domain folds only after the NMP and LID domains, reflecting the interwoven nature of the chain topology.
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Affiliation(s)
- Zhenxing Liu
- Department
of Physics, Beijing Normal University, Beijing 100875, China
| | - D. Thirumalai
- Department
of Chemistry, The University of Texas at
Austin, Austin, Texas 78712, United
States
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75
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Wang Z, Zhao Z, Li G, Zheng P. Single-Molecule Force Spectroscopy Reveals the Dynamic HgS Coordination Site in the De Novo-Designed Metalloprotein α 3DIV. J Phys Chem Lett 2022; 13:5372-5378. [PMID: 35678420 DOI: 10.1021/acs.jpclett.2c01316] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
The de novo-designed metalloprotein α3DIV binds to mercury via three cysteine residues under dynamic conditions. An unusual trigonal three-coordinate HgS3 site is formed in the protein in basic solution, whereas a linear two-coordinate HgS2 site is formed in acidic solution. Furthermore, it is unknown whether the two coordinated cysteines in the HgS2 site are fixed or not, which may lead to more dynamics. However, the signal for HgS2 sites with different cysteines may be similar or may be averaged and indistinguishable. To circumvent this problem, we adopt a single-molecule approach to study one mercury site at a time. Using atomic force microscopy-based single-molecule force spectroscopy, the protein is unfolded, and the HgS site is ruptured. The results confirm the formation of HgS3 and HgS2 sites at different pH values. Moreover, it is found that any two of the three cysteines in the protein bind to mercury in the HgS2 site.
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Affiliation(s)
- Ziyi Wang
- State Key Laboratory of Coordination Chemistry, Chemistry and Biomedicine Innovation Center (ChemBIC), School of Chemistry and Chemical Engineering, Nanjing University, Nanjing, Jiangsu 210023, P.R. China
| | - Zhongxing Zhao
- State Key Laboratory of Coordination Chemistry, Chemistry and Biomedicine Innovation Center (ChemBIC), School of Chemistry and Chemical Engineering, Nanjing University, Nanjing, Jiangsu 210023, P.R. China
| | - Guoqiang Li
- State Key Laboratory of Coordination Chemistry, Chemistry and Biomedicine Innovation Center (ChemBIC), School of Chemistry and Chemical Engineering, Nanjing University, Nanjing, Jiangsu 210023, P.R. China
| | - Peng Zheng
- State Key Laboratory of Coordination Chemistry, Chemistry and Biomedicine Innovation Center (ChemBIC), School of Chemistry and Chemical Engineering, Nanjing University, Nanjing, Jiangsu 210023, P.R. China
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76
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Serdiuk T, Manna M, Zhang C, Mari SA, Kulig W, Pluhackova K, Kobilka BK, Vattulainen I, Müller DJ. A cholesterol analog stabilizes the human β 2-adrenergic receptor nonlinearly with temperature. Sci Signal 2022; 15:eabi7031. [PMID: 35671340 PMCID: PMC10754352 DOI: 10.1126/scisignal.abi7031] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
In cell membranes, G protein-coupled receptors (GPCRs) interact with cholesterol, which modulates their assembly, stability, and conformation. Previous studies have shown how cholesterol modulates the structural properties of GPCRs at ambient temperature. Here, we characterized the mechanical, kinetic, and energetic properties of the human β2-adrenergic receptor (β2AR) in the presence and absence of the cholesterol analog cholesteryl hemisuccinate (CHS) at room temperature (25°C), at physiological temperature (37°C), and at high temperature (42°C). We found that CHS stabilized various structural regions of β2AR differentially, which changed nonlinearly with temperature. Thereby, the strongest effects were observed for structural regions that are important for receptor signaling. Moreover, at 37°C, but not at 25° or 42°C, CHS caused β2AR to increase and stabilize conformational substates to adopt to basal activity. These findings indicate that the nonlinear, temperature-dependent action of CHS in modulating the structural and functional properties of this GPCR is optimized for 37°C.
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Affiliation(s)
- Tetiana Serdiuk
- Department of Biosystems Science and Engineering, ETH Zurich, CH-4058 Basel, Switzerland
- Department of Biology, Institute of Molecular Systems Biology, ETH Zurich, CH-8093 Zurich, Switzerland
| | - Moutusi Manna
- Applied Phycology and Biotechnology Division, CSIR–Central Salt and Marine Chemicals Research Institute, Bhavnagar 364002, gujarat, india
| | - Cheng Zhang
- Department of Cellular Physiology and Medicine, Stanford University School of Medicine, Palo Alto, CA 94305, USA
- Department of Pharmacology and Chemical Biology, School of Medicine, University of Pittsburgh, Pittsburgh, PA 15261, USA
| | - Stefania A. Mari
- Department of Biosystems Science and Engineering, ETH Zurich, CH-4058 Basel, Switzerland
| | - Waldemar Kulig
- Department of Physics, University of Helsinki, P. O. Box 64, FI-00014 Helsinki, Finland
| | - Kristyna Pluhackova
- Department of Biosystems Science and Engineering, ETH Zurich, CH-4058 Basel, Switzerland
- Cluster of Excellence SimTech, Stuttgart Center for Simulation Science, University of Stuttgart, D-70569 Stuttgart, Germany
| | - Brian K. Kobilka
- Department of Cellular Physiology and Medicine, Stanford University School of Medicine, Palo Alto, CA 94305, USA
| | - Ilpo Vattulainen
- Department of Physics, University of Helsinki, P. O. Box 64, FI-00014 Helsinki, Finland
- Computational Physics Laboratory, Tampere University, P. O. Box 692, FI-33014 Tampere, Finland
| | - Daniel J. Müller
- Department of Biosystems Science and Engineering, ETH Zurich, CH-4058 Basel, Switzerland
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77
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Yang J, Wang Y, Qian HJ, Lu ZY, Gong Z, Liu H, Cui S. Force-induced hydrogen bonding between single polyformaldehyde chain and water. POLYMER 2022. [DOI: 10.1016/j.polymer.2022.125007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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78
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Mora M, Board S, Languin-Cattoën O, Masino L, Stirnemann G, Garcia-Manyes S. A Single-Molecule Strategy to Capture Non-native Intramolecular and Intermolecular Protein Disulfide Bridges. NANO LETTERS 2022; 22:3922-3930. [PMID: 35549281 PMCID: PMC9136921 DOI: 10.1021/acs.nanolett.2c00043] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/16/2022] [Revised: 02/23/2022] [Indexed: 05/04/2023]
Abstract
Non-native disulfide bonds are dynamic covalent bridges that form post-translationally between two cysteines within the same protein (intramolecular) or with a neighboring protein (intermolecular), frequently due to changes in the cellular redox potential. The reversible formation of non-native disulfides is intimately linked to alterations in protein function; while they can provide a mechanism to protect against cysteine overoxidation, they are also involved in the early stages of protein multimerization, a hallmark of several protein aggregation diseases. Yet their identification using current protein chemistry technology remains challenging, mainly because of their fleeting reactivity. Here, we use single-molecule spectroscopy AFM and molecular dynamics simulations to capture both intra- and intermolecular disulfide bonds in γD-crystallin, a cysteine-rich, structural human lens protein involved in age-related eye cataracts. Our approach showcases the power of mechanical force as a conformational probe in dynamically evolving proteins and presents a platform to detect non-native disulfide bridges with single-molecule resolution.
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Affiliation(s)
- Marc Mora
- Department
of Physics, Randall Centre for Cell and Molecular Biophysics and London
Centre for Nanotechnology, King’s
College London, Strand, WC2R 2LS London, United Kingdom
- Single
Molecule Mechanobiology Laboratory, The
Francis Crick Institute, 1 Midland Road, London NW1 1AT, London United
Kingdom
| | - Stephanie Board
- Department
of Physics, Randall Centre for Cell and Molecular Biophysics and London
Centre for Nanotechnology, King’s
College London, Strand, WC2R 2LS London, United Kingdom
- Single
Molecule Mechanobiology Laboratory, The
Francis Crick Institute, 1 Midland Road, London NW1 1AT, London United
Kingdom
| | - Olivier Languin-Cattoën
- CNRS
Laboratoire de Biochimie Théorique, Institut de Biologie Physico-Chimique, Université Paris Diderot,
Sorbonne Paris Cité, PSL Research University, 13 rue Pierre et Marie Curie, 75005 Paris, France
| | - Laura Masino
- Structural
Biology Science Technology Platform, The
Francis Crick Institute, 1 Midland Road London, NW1 1AT, United Kingdom
| | - Guillaume Stirnemann
- CNRS
Laboratoire de Biochimie Théorique, Institut de Biologie Physico-Chimique, Université Paris Diderot,
Sorbonne Paris Cité, PSL Research University, 13 rue Pierre et Marie Curie, 75005 Paris, France
| | - Sergi Garcia-Manyes
- Department
of Physics, Randall Centre for Cell and Molecular Biophysics and London
Centre for Nanotechnology, King’s
College London, Strand, WC2R 2LS London, United Kingdom
- Single
Molecule Mechanobiology Laboratory, The
Francis Crick Institute, 1 Midland Road, London NW1 1AT, London United
Kingdom
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79
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Wang H, Chen G, Li H. Templated folding of the RTX domain of the bacterial toxin adenylate cyclase revealed by single molecule force spectroscopy. Nat Commun 2022; 13:2784. [PMID: 35589788 PMCID: PMC9120197 DOI: 10.1038/s41467-022-30448-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2021] [Accepted: 04/26/2022] [Indexed: 11/18/2022] Open
Abstract
The RTX (repeats-in-toxin) domain of the bacterial toxin adenylate cyclase (CyaA) contains five RTX blocks (RTX-i to RTX-v) and its folding is essential for CyaA’s functions. It was shown that the C-terminal capping structure of RTX-v is critical for the whole RTX to fold. However, it is unknown how the folding signal transmits within the RTX domain. Here we use optical tweezers to investigate the interplay between the folding of RTX-iv and RTX-v. Our results show that RTX-iv alone is disordered, but folds into a Ca2+-loaded-β-roll structure in the presence of a folded RTX-v. Folding trajectories of RTX-iv-v reveal that the folding of RTX-iv is strictly conditional upon the folding of RTX-v, suggesting that the folding of RTX-iv is templated by RTX-v. This templating effect allows RTX-iv to fold rapidly, and provides significant mutual stabilization. Our study reveals a possible mechanism for transmitting the folding signal within the RTX domain. The authors use optical tweezers to show that the folding of repeats-in-toxin (RTX) block-iv in adenylate cyclase is templated by the folded RTX block-v. The findings suggest a possible mechanism for transmitting the folding signal in the RTX domain.
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Affiliation(s)
- Han Wang
- Department of Chemistry, University of British Columbia, Vancouver, BC, V6T 1Z1, Canada.,State Key Laboratory of Precision Measuring Technology and Instruments, School of Precision Instrument and Optoelectronics Engineering, Tianjin University, 300072, Tianjin, P. R. China
| | - Guojun Chen
- Department of Chemistry, University of British Columbia, Vancouver, BC, V6T 1Z1, Canada
| | - Hongbin Li
- Department of Chemistry, University of British Columbia, Vancouver, BC, V6T 1Z1, Canada.
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80
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Beaussart A, Canonico F, Mazon H, Hidalgo J, Cianférani S, Le Cordier H, Kriznik A, Rahuel-Clermont S. Probing the mechanism of the peroxiredoxin decamer interaction with its reductase sulfiredoxin from the single molecule to the solution scale. NANOSCALE HORIZONS 2022; 7:515-525. [PMID: 35234779 DOI: 10.1039/d2nh00037g] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Peroxiredoxins from the Prx1 subfamily (Prx) are highly regulated multifunctional proteins involved in oxidative stress response, redox signaling and cell protection. Prx is a homodimer that associates into a decamer. The monomer C-terminus plays intricate roles in Prx catalytic functions, decamer stability and interaction with its redox partner, the small reductase sulfiredoxin (Srx), that regulates the switching between Prx cellular functions. As only static structures of covalent Prx-Srx complexes have been reported, whether Srx binding dissociates the decameric assembly and how Prx subunit flexibility impacts complex formation are unknown. Here, we assessed the non-covalent interaction mechanism and dynamics in the solution of Saccharomyces cerevisiae Srx with the ten subunits of Prx Tsa1 at the decamer level via a combination of multiscale biophysical approaches including native mass spectrometry. We show that the ten subunits of the decamer can be saturated by ten Srx molecules and that the Tsa1 decamer in complex with Srx does not dissociate in solution. Furthermore, the binding events of atomic force microscopy (AFM) tip-grafted Srx molecules to Tsa1 individual subunits were relevant to the interactions between free molecules in solution. Combined with protein engineering and rapid kinetics, the observation of peculiar AFM force-distance signatures revealed that Tsa1 C-terminus flexibility controls Tsa1/Srx two-step binding and dynamics and determines the force-induced dissociation of Srx from each subunit of the decameric complex in a sequential or concerted mode. This combined approach from the solution to the single-molecule level offers promising prospects for understanding oligomeric protein interactions with their partners.
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Affiliation(s)
| | | | - Hortense Mazon
- Université de Lorraine, CNRS, IMoPA, F-54000 Nancy, France
| | - Jorge Hidalgo
- Université de Lorraine, CNRS, IMoPA, F-54000 Nancy, France
| | - Sarah Cianférani
- Laboratoire de Spectrométrie de Masse BioOrganique, Université de Strasbourg, CNRS, IPHC UMR 7178, 67000 Strasbourg, France
- Infrastructure Nationale de Protéomique ProFI - FR2048 CNRS CEA, 67087 Strasbourg, France
| | | | - Alexandre Kriznik
- Université de Lorraine, CNRS, IMoPA, F-54000 Nancy, France
- Université de Lorraine, CNRS, INSERM, UMS2008 IBSLor, Biophysics and Structural Biology core facility, F-54000 Nancy, France.
| | - Sophie Rahuel-Clermont
- Université de Lorraine, CNRS, IMoPA, F-54000 Nancy, France
- Université de Lorraine, CNRS, INSERM, UMS2008 IBSLor, Biophysics and Structural Biology core facility, F-54000 Nancy, France.
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81
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Gil-Redondo JC, Weber A, Toca-Herrera JL. Measuring (biological) materials mechanics with atomic force microscopy. 3. Mechanical unfolding of biopolymers. Microsc Res Tech 2022; 85:3025-3036. [PMID: 35502131 PMCID: PMC9543778 DOI: 10.1002/jemt.24136] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2022] [Accepted: 04/13/2022] [Indexed: 11/28/2022]
Abstract
Biopolymers, such as polynucleotides, polypeptides and polysaccharides, are macromolecules that direct most of the functions in living beings. Studying the mechanical unfolding of biopolymers provides important information about their molecular elasticity and mechanical stability, as well as their energy landscape, which is especially important in proteins, since their three‐dimensional structure is essential for their correct activity. In this primer, we present how to study the mechanical properties of proteins with atomic force microscopy and how to obtain information about their stability and energetic landscape. In particular, we discuss the preparation of polyprotein constructs suitable for AFM single molecule force spectroscopy (SMFS), describe the parameters used in our force‐extension SMFS experiments and the models and equations employed in the analysis of the data. As a practical example, we show the effect of the temperature on the unfolding force, the distance to the transition state, the unfolding rate at zero force, the height of the transition state barrier, and the spring constant of the protein for a construct containing nine repeats of the I27 domain from the muscle protein titin.
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Affiliation(s)
- Juan Carlos Gil-Redondo
- Institute of Biophysics, Department of Nanobiotechnology, University of Natural Resources and Life Sciences Vienna (BOKU), Vienna, Austria
| | - Andreas Weber
- Institute of Biophysics, Department of Nanobiotechnology, University of Natural Resources and Life Sciences Vienna (BOKU), Vienna, Austria
| | - José L Toca-Herrera
- Institute of Biophysics, Department of Nanobiotechnology, University of Natural Resources and Life Sciences Vienna (BOKU), Vienna, Austria
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82
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Monroe L, Kihara D. Using steered molecular dynamic tension for assessing quality of computational protein structure models. J Comput Chem 2022; 43:1140-1150. [PMID: 35475517 DOI: 10.1002/jcc.26876] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2021] [Revised: 02/16/2022] [Accepted: 04/15/2022] [Indexed: 11/12/2022]
Abstract
The native structures of proteins, except for notable exceptions of intrinsically disordered proteins, in general take their most stable conformation in the physiological condition to maintain their structural framework so that their biological function can be properly carried out. Experimentally, the stability of a protein can be measured by several means, among which the pulling experiment using the atomic force microscope (AFM) stands as a unique method. AFM directly measures the resistance from unfolding, which can be quantified from the observed force-extension profile. It has been shown that key features observed in an AFM pulling experiment can be well reproduced by computational molecular dynamics simulations. Here, we applied computational pulling for estimating the accuracy of computational protein structure models under the hypothesis that the structural stability would positively correlated with the accuracy, i.e. the closeness to the native, of a model. We used in total 4929 structure models for 24 target proteins from the Critical Assessment of Techniques of Structure Prediction (CASP) and investigated if the magnitude of the break force, that is, the force required to rearrange the model's structure, from the force profile was sufficient information for selecting near-native models. We found that near-native models can be successfully selected by examining their break forces suggesting that high break force indeed indicates high stability of models. On the other hand, there were also near-native models that had relatively low peak forces. The mechanisms of the stability exhibited by the break forces were explored and discussed.
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Affiliation(s)
- Lyman Monroe
- Department of Biological Sciences, Purdue University, West Lafayette, Indiana, USA
| | - Daisuke Kihara
- Department of Biological Sciences, Purdue University, West Lafayette, Indiana, USA.,Department of Computer Science, Purdue University, West Lafayette, Indiana, USA.,Purdue Center for Cancer Research, Purdue University, West Lafayette, Indiana, USA
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83
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Shi S, Wu T, Zheng P. Direct Measurements of the Cobalt-thiolate Bonds Strength in Rubredoxin by Single-Molecule Force Spectroscopy. Chembiochem 2022; 23:e202200165. [PMID: 35475313 DOI: 10.1002/cbic.202200165] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2022] [Revised: 04/26/2022] [Indexed: 11/07/2022]
Abstract
Cobalt is a trace transition metal. Although it is not abundant on earth, tens of cobalt-containing proteins exist in life. Moreover, the characteristic spectrum of Co(II) ion makes it a powerful probe for the characterization of metal-binding proteins through the formation of cobalt-ligand bonds. Since most of these natural and artificial cobalt-containing proteins are stable, we believe that these cobalt-ligand bonds in the protein system are also mechanically stable. To prove this, we used atomic force microscopy-based single-molecule force spectroscopy (AFM-SMFS) to directly measure the rupture force of Co(II)-thiolate bond in Co-substituted rubredoxin (CoRD). By combining the chemical denature/renature method for building metalloprotein and cysteine coupling-based polyprotein construction strategy, we successfully prepared the polyprotein sample (CoRD) n suitable for single-molecule study. Thus, we quantified the strength of Co(II)-thiolate bonds in rubredoxin with a rupture force of ~140 pN, revealing that the bond is a stable chemical bond. In addition, the Co-S bond is more labile than the Zn-S bond in proteins, similar to the result from the metal-competing titration experiment.
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Affiliation(s)
- Shengchao Shi
- Nanjing University, School of Chemistry and Chemical Engineering, CHINA
| | - Tao Wu
- Nanjing University, School of Chemistry and Chemical Engineering, CHINA
| | - Peng Zheng
- Nanjing University, School of Chemistry and Chemical Engineering, 168 Xianlin Ave, Nanjing, Jiangsu Province, 210023, Nanjing, CHINA
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84
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85
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Abstract
In the dynamic environment of the airways, where SARS-CoV-2 infections are initiated by binding to human host receptor ACE2, mechanical stability of the viral attachment is a crucial fitness advantage. Using single-molecule force spectroscopy techniques, we mimic the effect of coughing and sneezing, thereby testing the force stability of SARS-CoV-2 RBD:ACE2 interaction under physiological conditions. Our results reveal a higher force stability of SARS-CoV-2 binding to ACE2 compared to SARS-CoV-1, causing a possible fitness advantage. Our assay is sensitive to blocking agents preventing RBD:ACE2 bond formation. It will thus provide a powerful approach to investigate the modes of action of neutralizing antibodies and other agents designed to block RBD binding to ACE2 that are currently developed as potential COVID-19 therapeutics. Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infections are initiated by attachment of the receptor-binding domain (RBD) on the viral Spike protein to angiotensin-converting enzyme-2 (ACE2) on human host cells. This critical first step occurs in dynamic environments, where external forces act on the binding partners and avidity effects play an important role, creating an urgent need for assays that can quantitate SARS-CoV-2 interactions with ACE2 under mechanical load. Here, we introduce a tethered ligand assay that comprises the RBD and the ACE2 ectodomain joined by a flexible peptide linker. Using magnetic tweezers and atomic force spectroscopy as highly complementary single-molecule force spectroscopy techniques, we investigate the RBD:ACE2 interaction over the whole physiologically relevant force range. We combine the experimental results with steered molecular dynamics simulations and observe and assign fully consistent unbinding and unfolding events across the three techniques, enabling us to establish ACE2 unfolding as a molecular fingerprint. Measuring at forces of 2 to 5 pN, we quantify the force dependence and kinetics of the RBD:ACE2 bond in equilibrium. We show that the SARS-CoV-2 RBD:ACE2 interaction has higher mechanical stability, larger binding free energy, and a lower dissociation rate compared to SARS-CoV-1, which helps to rationalize the different infection patterns of the two viruses. By studying how free ACE2 outcompetes tethered ACE2, we show that our assay is sensitive to prevention of bond formation by external binders. We expect our results to provide a way to investigate the roles of viral mutations and blocking agents for targeted pharmaceutical intervention.
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86
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Chetrit E, Sharma S, Maayan U, Pelah MG, Klausner Z, Popa I, Berkovich R. Nonexponential kinetics in captured in sequential unfolding of polyproteins over a range of loads. Curr Res Struct Biol 2022; 4:106-117. [PMID: 35540955 PMCID: PMC9079174 DOI: 10.1016/j.crstbi.2022.04.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2021] [Revised: 04/15/2022] [Accepted: 04/19/2022] [Indexed: 11/08/2022] Open
Abstract
While performing under mechanical loads in vivo, polyproteins are vitally involved in cellular mechanisms such as regulation of tissue elasticity and mechano-transduction by unfolding their comprising domains and extending them. It is widely thought that the process of sequential unfolding of polyproteins follows an exponential kinetics as the individual unfolding events exhibit identical and identically distributed (iid) Poisson behavior. However, it was shown that under high loads, the sequential unfolding kinetics displays nonexponential kinetics that alludes to aging by a subdiffusion process. Statistical order analysis of this kinetics indicated that the individual unfolding events are not iid, and cannot be defined as a Poisson (memoryless) process. Based on numerical simulations it was argued that this behavior becomes less pronounced with lowering the load, therefore it is to be expected that polyproteins unfolding under lower forces will follow a Poisson behavior. This expectation serves as the motivation of the current study, in which we investigate the effect of force lowering on the unfolding kinetics of Poly-L8 under varying loads, specifically high (150, 100 pN) and moderate-low (45, 30, 20 pN) forces. We found that a hierarchy among the unfolding events still exists even under low loads, again resulting in nonexponential behavior. We observe that analyzing the dwell-time distributions with stretched-exponentials and power laws give rise to different phenomenological trends. Using statistical order analysis, we demonstrated that even under the lowest load, the sequential unfolding cannot be considered as iid, in accord with the power law distribution. Additional free energy analysis revealed the contribution of the unfolded segments elasticity that scales with the force on the overall one-dimensional contour of the energy landscape, but more importantly, it discloses the hierarchy within the activation barriers during sequential unfolding that account for the observed nonexponentiality. Poly-L8 unfolding shows nonexponential kinetics at forces ranging from 150 to 20 pN. Different phenomenological trends are observed for the dwell-time distributions. The unfolding events were shown to be dependent and not identically distributed. Free energy analysis reveals elastic impact and hierarchy in the unfolding barriers.
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87
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Ferenczy GG, Kellermayer M. Contribution of Hydrophobic Interactions to Protein Mechanical Stability. Comput Struct Biotechnol J 2022; 20:1946-1956. [PMID: 35521554 PMCID: PMC9062142 DOI: 10.1016/j.csbj.2022.04.025] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/25/2021] [Revised: 04/07/2022] [Accepted: 04/17/2022] [Indexed: 11/26/2022] Open
Abstract
The role of hydrophobic and polar interactions in providing thermodynamic stability to folded proteins has been intensively studied, but the relative contribution of these interactions to the mechanical stability is less explored. We used steered molecular dynamics simulations with constant-velocity pulling to generate force-extension curves of selected protein domains and monitor hydrophobic surface unravelling upon extension. Hydrophobic contribution was found to vary between one fifth and one third of the total force while the rest of the contribution is attributed primarily to hydrogen bonds. Moreover, hydrophobic force peaks were shifted towards larger protein extensions with respect to the force peaks attributed to hydrogen bonds. The higher importance of hydrogen bonds compared to hydrophobic interactions in providing mechanical resistance is in contrast with the relative importance of the hydrophobic interactions in providing thermodynamic stability of proteins. The different contributions of these interactions to the mechanical stability are explained by the steeper free energy dependence of hydrogen bonds compared to hydrophobic interactions on the relative positions of interacting atoms. Comparative analyses for several protein domains revealed that the variation of hydrophobic forces is modest, while the contribution of hydrogen bonds to the force peaks becomes increasingly important for mechanically resistant protein domains.
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88
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Hu R, Zhao S, Chen F, Shangguan Y, Zheng Q. Effect of sacrificial bond on molecular dynamics and rheological behavior of hybrid butadiene‐styrene‐vinylpyridine rubber vulcanizates with reversible sacrificial network. JOURNAL OF POLYMER SCIENCE 2022. [DOI: 10.1002/pol.20210905] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Affiliation(s)
- Rongyan Hu
- MOE Key Laboratory of Macromolecule Synthesis and Functionalization, Department of Polymer Science and Engineering Zhejiang University Hangzhou China
| | - Shunjie Zhao
- MOE Key Laboratory of Macromolecule Synthesis and Functionalization, Department of Polymer Science and Engineering Zhejiang University Hangzhou China
| | - Feng Chen
- MOE Key Laboratory of Macromolecule Synthesis and Functionalization, Department of Polymer Science and Engineering Zhejiang University Hangzhou China
| | - Yonggang Shangguan
- MOE Key Laboratory of Macromolecule Synthesis and Functionalization, Department of Polymer Science and Engineering Zhejiang University Hangzhou China
- Shanxi‐Zheda Institute of Advanced Materials and Chemical Engineering Taiyuan China
| | - Qiang Zheng
- MOE Key Laboratory of Macromolecule Synthesis and Functionalization, Department of Polymer Science and Engineering Zhejiang University Hangzhou China
- Shanxi‐Zheda Institute of Advanced Materials and Chemical Engineering Taiyuan China
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89
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Ge X, Zhang W, Putnis CV, Wang L. Molecular mechanisms for the humic acid-enhanced formation of the ordered secondary structure of a conserved catalytic domain in phytase. Phys Chem Chem Phys 2022; 24:4493-4503. [PMID: 35113120 DOI: 10.1039/d2cp00054g] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
Changes in the secondary structure of phytase, particularly the conserved active catalytic domain (ACD, SRHGVRAPHD) are extremely important for the varied catalytic activity during hydrolyzing phytate in the presence of humic acid (HA). However, little is known about the molecular-scale mechanisms of how HA influences the secondary structure of ACD found in phytase. First, in situ surface-enhanced Raman spectroscopy (SERS) results show the secondary structure transformation of ACD from the unordered random coil to the ordered β-sheet structure after treatment with HA. Then, we use an atomic force microscopy (AFM)-based single-molecule force spectroscopy (SMFS) technique that can in situ directly probe the single-molecule interaction of ACD with HA and underlying changes in ACD secondary structure in the approach-retraction cycles in real time. Based on the SMFS results, we further detect the HA-enhanced formation of H-bonding between amide groups in the ACD backbone after noncovalently interacting with HA in the absence of phytate. Following the addition of phytate, the calculated contour length (Lc) and the free energies (ΔGb) of functional groups within ACD(-1/2) binding to mica/HA collectively demonstrate the formation of the organized intermediate structural state of ACD following its covalent binding to phytate. These spectroscopic and single-molecule determinations provide the molecular-scale understanding regarding the detailed mechanisms of HA-enhancement of the ordered β-sheet secondary structure of ACD through chemical functionalities in ACD noncovalently interacting with HA. Therefore, we suggest that similar studies of the interactions of other soil enzymes and plant nutrients may reveal predominant roles of dissolved organic matter (DOM) in controlling elemental cycling and fate for sustainable agriculture development.
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Affiliation(s)
- Xinfei Ge
- College of Resources and Environment, Huazhong Agricultural University, Wuhan 430070, China.
| | - Wenjun Zhang
- College of Resources and Environment, Huazhong Agricultural University, Wuhan 430070, China.
| | - Christine V Putnis
- Institut für Mineralogie, University of Münster, 48149 Münster, Germany.,School of Molecular and Life Science, Curtin University, Perth 6845, Australia
| | - Lijun Wang
- College of Resources and Environment, Huazhong Agricultural University, Wuhan 430070, China.
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90
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Abstract
Single-molecule magnetic tweezers deliver magnetic force and torque to single target molecules, permitting the study of dynamic changes in biomolecular structures and their interactions. Because the magnetic tweezer setups can generate magnetic fields that vary slowly over tens of millimeters-far larger than the nanometer scale of the single molecule events being observed-this technique can maintain essentially constant force levels during biochemical experiments while generating a biologically meaningful force on the order of 1-100 pN. When using bead-tether constructs to pull on single molecules, smaller magnetic beads and shorter submicrometer tethers improve dynamic response times and measurement precision. In addition, employing high-speed cameras, stronger light sources, and a graphics programming unit permits true high-resolution single-molecule magnetic tweezers that can track nanometer changes in target molecules on a millisecond or even submillisecond time scale. The unique force-clamping capacity of the magnetic tweezer technique provides a way to conduct measurements under near-equilibrium conditions and directly map the energy landscapes underlying various molecular phenomena. High-resolution single-molecule magnetic tweezers can thus be used to monitor crucial conformational changes in single-protein molecules, including those involved in mechanotransduction and protein folding. Expected final online publication date for the Annual Review of Biochemistry, Volume 91 is June 2022. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.
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Affiliation(s)
- Hyun-Kyu Choi
- Wallace H. Coulter Department of Biomedical Engineering and Parker H. Petit Institute for Bioengineering and Bioscience, Georgia Institute of Technology, Atlanta, Georgia, USA
| | - Hyun Gyu Kim
- School of Biological Sciences and Institute for Molecular Biology and Genetics, Seoul National University, Seoul, South Korea;
| | - Min Ju Shon
- Department of Physics and School of Interdisciplinary Bioscience and Bioengineering, Pohang University of Science & Technology (POSTECH), Pohang, South Korea;
| | - Tae-Young Yoon
- School of Biological Sciences and Institute for Molecular Biology and Genetics, Seoul National University, Seoul, South Korea;
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91
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Sun W, Gao X, Lei H, Wang W, Cao Y. Biophysical Approaches for Applying and Measuring Biological Forces. ADVANCED SCIENCE (WEINHEIM, BADEN-WURTTEMBERG, GERMANY) 2022; 9:e2105254. [PMID: 34923777 PMCID: PMC8844594 DOI: 10.1002/advs.202105254] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/15/2021] [Indexed: 05/13/2023]
Abstract
Over the past decades, increasing evidence has indicated that mechanical loads can regulate the morphogenesis, proliferation, migration, and apoptosis of living cells. Investigations of how cells sense mechanical stimuli or the mechanotransduction mechanism is an active field of biomaterials and biophysics. Gaining a further understanding of mechanical regulation and depicting the mechanotransduction network inside cells require advanced experimental techniques and new theories. In this review, the fundamental principles of various experimental approaches that have been developed to characterize various types and magnitudes of forces experienced at the cellular and subcellular levels are summarized. The broad applications of these techniques are introduced with an emphasis on the difficulties in implementing these techniques in special biological systems. The advantages and disadvantages of each technique are discussed, which can guide readers to choose the most suitable technique for their questions. A perspective on future directions in this field is also provided. It is anticipated that technical advancement can be a driving force for the development of mechanobiology.
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Affiliation(s)
- Wenxu Sun
- School of SciencesNantong UniversityNantong226019P. R. China
| | - Xiang Gao
- Key Laboratory of Intelligent Optical Sensing and IntegrationNational Laboratory of Solid State Microstructureand Department of PhysicsCollaborative Innovation Center of Advanced MicrostructuresNanjing UniversityNanjing210023P. R. China
- Institute of Brain ScienceNanjing UniversityNanjing210023P. R. China
| | - Hai Lei
- Key Laboratory of Intelligent Optical Sensing and IntegrationNational Laboratory of Solid State Microstructureand Department of PhysicsCollaborative Innovation Center of Advanced MicrostructuresNanjing UniversityNanjing210023P. R. China
- Institute of Brain ScienceNanjing UniversityNanjing210023P. R. China
- Chemistry and Biomedicine Innovation CenterNanjing UniversityNanjing210023P. R. China
| | - Wei Wang
- Key Laboratory of Intelligent Optical Sensing and IntegrationNational Laboratory of Solid State Microstructureand Department of PhysicsCollaborative Innovation Center of Advanced MicrostructuresNanjing UniversityNanjing210023P. R. China
- Institute of Brain ScienceNanjing UniversityNanjing210023P. R. China
| | - Yi Cao
- Key Laboratory of Intelligent Optical Sensing and IntegrationNational Laboratory of Solid State Microstructureand Department of PhysicsCollaborative Innovation Center of Advanced MicrostructuresNanjing UniversityNanjing210023P. R. China
- Institute of Brain ScienceNanjing UniversityNanjing210023P. R. China
- MOE Key Laboratory of High Performance Polymer Materials and TechnologyDepartment of Polymer Science & EngineeringCollege of Chemistry & Chemical EngineeringNanjing UniversityNanjing210023P. R. China
- Chemistry and Biomedicine Innovation CenterNanjing UniversityNanjing210023P. R. China
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92
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Yang T, Park C, Rah SH, Shon MJ. Nano-Precision Tweezers for Mechanosensitive Proteins and Beyond. Mol Cells 2022; 45:16-25. [PMID: 35114644 PMCID: PMC8819490 DOI: 10.14348/molcells.2022.2026] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2021] [Revised: 01/10/2022] [Accepted: 01/12/2022] [Indexed: 11/27/2022] Open
Abstract
Mechanical forces play pivotal roles in regulating cell shape, function, and fate. Key players that govern the mechanobiological interplay are the mechanosensitive proteins found on cell membranes and in cytoskeleton. Their unique nanomechanics can be interrogated using single-molecule tweezers, which can apply controlled forces to the proteins and simultaneously measure the ensuing structural changes. Breakthroughs in high-resolution tweezers have enabled the routine monitoring of nanometer-scale, millisecond dynamics as a function of force. Undoubtedly, the advancement of structural biology will be further fueled by integrating static atomic-resolution structures and their dynamic changes and interactions observed with the force application techniques. In this minireview, we will introduce the general principles of single-molecule tweezers and their recent applications to the studies of force-bearing proteins, including the synaptic proteins that need to be categorized as mechanosensitive in a broad sense. We anticipate that the impact of nano-precision approaches in mechanobiology research will continue to grow in the future.
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Affiliation(s)
- Taehyun Yang
- Department of Physics, Pohang University of Science and Technology, Pohang 37673, Korea
| | - Celine Park
- Department of Physics, Pohang University of Science and Technology, Pohang 37673, Korea
| | - Sang-Hyun Rah
- Department of Physics, Pohang University of Science and Technology, Pohang 37673, Korea
| | - Min Ju Shon
- Department of Physics, Pohang University of Science and Technology, Pohang 37673, Korea
- School of Interdisciplinary Bioscience and Bioengineering, Pohang University of Science and Technology, Pohang 37673, Korea
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93
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Duanis-Assaf T, Hu T, Lavie M, Zhang Z, Reches M. Understanding the Adhesion Mechanism of Hydroxyapatite-Binding Peptide. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2022; 38:968-978. [PMID: 34995466 PMCID: PMC8793143 DOI: 10.1021/acs.langmuir.1c02293] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/29/2021] [Revised: 12/21/2021] [Indexed: 05/31/2023]
Abstract
Understanding the interactions between the protein collagen and hydroxyapatite is of high importance for understanding biomineralization and bone formation. Here, we undertook a reductionist approach and studied the interactions between a short peptide and hydroxyapatite. The peptide was selected from a phage-display library for its high affinity to hydroxyapatite. To study its interactions with hydroxyapatite, we performed an alanine scan to determine the contribution of each residue. The interactions of the different peptide derivatives were studied using a quartz crystal microbalance with dissipation monitoring and with single-molecule force spectroscopy by atomic force microscopy. Our results suggest that the peptide binds via electrostatic interactions between cationic moieties of the peptide and the negatively charged groups on the crystal surface. Furthermore, our findings show that cationic residues have a crucial role in binding. Using molecular dynamics simulations, we show that the peptide structure is a contributing factor to the adhesion mechanism. These results suggest that even small conformational changes can have a significant effect on peptide adhesion. We suggest that a bent structure of the peptide allows it to strongly bind hydroxyapatite. The results presented in this study improve our understanding of peptide adhesion to hydroxyapatite. On top of physical interactions between the peptide and the surface, peptide structure contributes to adhesion. Unveiling these processes contributes to our understanding of more complex biological systems. Furthermore, it may help in the design of de novo peptides to be used as functional groups for modifying the surface of hydroxyapatite.
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Affiliation(s)
- Tal Duanis-Assaf
- Institute
of Chemistry and The Center for Nanoscience and Nanotechnology, The Hebrew University of Jerusalem, Jerusalem 91904, Israel
| | - Tan Hu
- Institute
of Chemistry and The Center for Nanoscience and Nanotechnology, The Hebrew University of Jerusalem, Jerusalem 91904, Israel
- College
of Food Science and Technology, Huazhong
Agricultural University, Wuhan, Hubei 430070, People’s Republic of China
- Key
Laboratory of Environment Correlative Dietology, Huazhong Agricultural
University, Ministry of Education, Wuhan, Hubei 430070, People’s Republic of China
| | - Maayan Lavie
- Institute
of Chemistry and The Center for Nanoscience and Nanotechnology, The Hebrew University of Jerusalem, Jerusalem 91904, Israel
| | - Zhuo Zhang
- College
of Food Science and Technology, Huazhong
Agricultural University, Wuhan, Hubei 430070, People’s Republic of China
- Key
Laboratory of Environment Correlative Dietology, Huazhong Agricultural
University, Ministry of Education, Wuhan, Hubei 430070, People’s Republic of China
| | - Meital Reches
- Institute
of Chemistry and The Center for Nanoscience and Nanotechnology, The Hebrew University of Jerusalem, Jerusalem 91904, Israel
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94
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Nanosurgical Manipulation of Titin and Its M-Complex. NANOMATERIALS 2022; 12:nano12020178. [PMID: 35055197 PMCID: PMC8779236 DOI: 10.3390/nano12020178] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/03/2021] [Revised: 01/01/2022] [Accepted: 01/04/2022] [Indexed: 01/21/2023]
Abstract
Titin is a multifunctional filamentous protein anchored in the M-band, a hexagonally organized supramolecular lattice in the middle of the muscle sarcomere. Functionally, the M-band is a framework that cross-links myosin thick filaments, organizes associated proteins, and maintains sarcomeric symmetry via its structural and putative mechanical properties. Part of the M-band appears at the C-terminal end of isolated titin molecules in the form of a globular head, named here the “M-complex”, which also serves as the point of head-to-head attachment of titin. We used high-resolution atomic force microscopy and nanosurgical manipulation to investigate the topographical and internal structure and local mechanical properties of the M-complex and its associated titin molecules. We find that the M-complex is a stable structure that corresponds to the transverse unit of the M-band organized around the myosin thick filament. M-complexes may be interlinked into an M-complex array that reflects the local structural and mechanical status of the transversal M-band lattice. Local segments of titin and the M-complex could be nanosurgically manipulated to achieve extension and domain unfolding. Long threads could be pulled out of the M-complex, suggesting that it is a compact supramolecular reservoir of extensible filaments. Nanosurgery evoked an unexpected volume increment in the M-complex, which may be related to its function as a mechanical spacer. The M-complex thus displays both elastic and plastic properties which support the idea that the M-band may be involved in mechanical functions within the muscle sarcomere.
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95
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Schönfelder J, Alonso-Caballero A, Perez-Jimenez R. Mechanochemical Evolution of Disulfide Bonds in Proteins. Methods Mol Biol 2022; 2376:283-300. [PMID: 34845615 DOI: 10.1007/978-1-0716-1716-8_15] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Disulfide bonds play a pivotal role in the mechanical stability of proteins. Numerous proteins that are known to be exposed to mechanical forces in vivo contain disulfide bonds. The presence of cryptic disulfide bonds in a protein structure may be related to its resistance to an applied mechanical force. Disulfide bonds in proteins tend to be highly conserved but their evolution might be directly related to the evolution of the protein mechanical stability. Hence, tracking the evolution of disulfide bonds in a protein can help to derive crucial stability/function correlations in proteins that are exposed to mechanical forces. Phylogenic analysis and ancestral sequence reconstruction (ASR) allow tracking the evolution of proteins from the past ancestors to our modern days and also establish correlations between proteins from different species. In addition, ASR can be combined with single-molecule force spectroscopy (smFS) to investigate the mechanical properties of proteins including the occurrence and function of disulfide bonds. Here we present a detailed protocol to study the mechanochemical evolution of proteins using a fragment of the giant muscle protein titin as example. The protocol can be easily adapted to AFS studies of any resurrected mechanical force bearing protein of interest.
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Affiliation(s)
- Jörg Schönfelder
- CIC nanoGUNE, San Sebastián, Spain
- IMDEA Nanosciences, Madrid, Spain
| | | | - Raul Perez-Jimenez
- CIC nanoGUNE, San Sebastián, Spain.
- IKERBASQUE, Basque Foundation for Science, Bilbao, Spain.
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96
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马 雪. Single Molecule Magnetic Tweezers Study of Unfolding Kinetics of Acylphosphatase. Biophysics (Nagoya-shi) 2022. [DOI: 10.12677/biphy.2022.102003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
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97
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Ray A, Passiu C, Nasuda M, Ramakrishna SN, Rossi A, Kuzuya A, Spencer ND, Yamakoshi Y. Reactive-Oxygen-Species-Mediated Surface Oxidation of Single-Molecule DNA Origami by an Atomic Force Microscope Tip-Mounted C 60 Photocatalyst. ACS NANO 2021; 15:19256-19265. [PMID: 34817171 DOI: 10.1021/acsnano.1c04953] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
A tripod molecule incorporating a C60 photocatalyst into a rigid scaffold with disulfide legs was designed and synthesized for the stable and robust attachment of C60 onto an Au-coated atomic force microscope (AFM) tip. The "tripod-C60" was immobilized onto the tip by forming S-Au bonds in the desired orientation and a dispersed manner, rendering it suitable for the oxidation and scission of single molecules on a countersurface, thereby functioning as "molecular shears". A DNA origami with a well-defined structure was chosen as the substrate for the tip-induced oxidation. The gold-coated, C60-functionalized AFM tip was used for both AFM imaging and oxidation of DNA origami upon visible-light irradiation. The localized and temporally controlled oxidative damage of DNA origami was successfully performed at the single-molecule level via singlet-oxygen (1O2) generation from the immobilized C60 on the AFM tip. This oxidative damage to DNA origami can be carried out under ambient conditions in a fluid cell at room temperature, rendering it well-suited for the manipulation of a variety of species on surfaces via a spatially and temporally controlled oxidation reaction triggered by 1O2 locally generated from the immobilized C60 on the AFM tip.
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Affiliation(s)
- Ankita Ray
- Laboratorium für Organische Chemie, ETH Zürich, Vladimir-Prelog-Weg 3, CH 8093 Zürich, Switzerland
| | - Cristiana Passiu
- Laboratory for Surface Science and Technology, Department of Materials, ETH Zürich, Vladimir-Prelog-Weg 5, CH 8093 Zürich, Switzerland
| | - Masayuki Nasuda
- Laboratorium für Organische Chemie, ETH Zürich, Vladimir-Prelog-Weg 3, CH 8093 Zürich, Switzerland
| | - Shivaprakash N Ramakrishna
- Laboratory for Surface Science and Technology, Department of Materials, ETH Zürich, Vladimir-Prelog-Weg 5, CH 8093 Zürich, Switzerland
| | - Antonella Rossi
- Laboratory for Surface Science and Technology, Department of Materials, ETH Zürich, Vladimir-Prelog-Weg 5, CH 8093 Zürich, Switzerland
- Dipartimento di Scienze Chimiche e Geologiche, Università degli Studi di Cagliari, Cittadella Universitaria di Monserrato, I-09100 Cagliari, Italy
| | - Akinori Kuzuya
- Department of Chemistry and Materials Engineering, Kansai University, Yamate-cho 3-3-35, Suita, 564-8680 Osaka, Japan
| | - Nicholas D Spencer
- Laboratory for Surface Science and Technology, Department of Materials, ETH Zürich, Vladimir-Prelog-Weg 5, CH 8093 Zürich, Switzerland
| | - Yoko Yamakoshi
- Laboratorium für Organische Chemie, ETH Zürich, Vladimir-Prelog-Weg 3, CH 8093 Zürich, Switzerland
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98
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Carlucci LA, Thomas WE. Modification to axial tracking for mobile magnetic microspheres. BIOPHYSICAL REPORTS 2021; 1:100031. [PMID: 35965968 PMCID: PMC9371438 DOI: 10.1016/j.bpr.2021.100031] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/07/2021] [Accepted: 11/04/2021] [Indexed: 11/30/2022]
Abstract
Three-dimensional particle tracking is a routine experimental procedure for various biophysical applications including magnetic tweezers. A common method for tracking the axial position of particles involves the analysis of diffraction rings whose pattern depends sensitively on the axial position of the bead relative to the focal plane. To infer the axial position, the observed rings are compared with reference images of a bead at known axial positions. Often the precision or accuracy of these algorithms is measured on immobilized beads over a limited axial range, while many experiments are performed using freely mobile beads. This inconsistency raises the possibility of incorrect estimates of experimental uncertainty. By manipulating magnetic beads in a bidirectional magnetic tweezer setup, we evaluated the error associated with tracking mobile magnetic beads and found that the error of tracking a moving magnetic bead increases by almost an order of magnitude compared to the error of tracking a stationary bead. We found that this additional error can be ameliorated by excluding the center-most region of the diffraction ring pattern from tracking analysis. Evaluation of the limitations of a tracking algorithm is essential for understanding the error associated with a measurement. These findings promise to bring increased resolution to three-dimensional bead tracking of magnetic microspheres.
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Affiliation(s)
- Laura A. Carlucci
- Department of Bioengineering, University of Washington, Seattle, Washington
| | - Wendy E. Thomas
- Department of Bioengineering, University of Washington, Seattle, Washington
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99
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Pan J, Kmieciak T, Liu YT, Wildenradt M, Chen YS, Zhao Y. Quantifying molecular- to cellular-level forces in living cells. JOURNAL OF PHYSICS D: APPLIED PHYSICS 2021; 54:483001. [PMID: 34866655 PMCID: PMC8635116 DOI: 10.1088/1361-6463/ac2170] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Mechanical cues have been suggested to play an important role in cell functions and cell fate determination, however, such physical quantities are challenging to directly measure in living cells with single molecule sensitivity and resolution. In this review, we focus on two main technologies that are promising in probing forces at the single molecule level. We review their theoretical fundamentals, recent technical advancements, and future directions, tailored specifically for interrogating mechanosensitive molecules in live cells.
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Affiliation(s)
- Jason Pan
- Department of Electrical and Computer Engineering, University of Illinois at Urbana-Champaign, Urbana, IL 61801, United States of America
| | - Tommy Kmieciak
- Department of Engineering Physics, University of Illinois at Urbana-Champaign, Urbana, IL 61801, United States of America
| | - Yen-Ting Liu
- Department of Electrical and Computer Engineering, University of Illinois at Urbana-Champaign, Urbana, IL 61801, United States of America
| | - Matthew Wildenradt
- Department of Electrical and Computer Engineering, University of Illinois at Urbana-Champaign, Urbana, IL 61801, United States of America
| | - Yun-Sheng Chen
- Department of Electrical and Computer Engineering, University of Illinois at Urbana-Champaign, Urbana, IL 61801, United States of America
- Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, Urbana, IL 61801, United States of America
| | - Yang Zhao
- Department of Electrical and Computer Engineering, University of Illinois at Urbana-Champaign, Urbana, IL 61801, United States of America
- Holonyak Micro and Nanotechnology Laboratory, University of Illinois at Urbana-Champaign, 208 N. Wright Street, Urbana, IL 61801, United States of America
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100
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Mechanobiology of muscle and myofibril morphogenesis. Cells Dev 2021; 168:203760. [PMID: 34863916 DOI: 10.1016/j.cdev.2021.203760] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2021] [Revised: 11/22/2021] [Accepted: 11/22/2021] [Indexed: 01/05/2023]
Abstract
Muscles generate forces for animal locomotion. The contractile apparatus of muscles is the sarcomere, a highly regular array of large actin and myosin filaments linked by gigantic titin springs. During muscle development many sarcomeres assemble in series into long periodic myofibrils that mechanically connect the attached skeleton elements. Thus, ATP-driven myosin forces can power movement of the skeleton. Here we review muscle and myofibril morphogenesis, with a particular focus on their mechanobiology. We describe recent progress on the molecular structure of sarcomeres and their mechanical connections to the skeleton. We discuss current models predicting how tension coordinates the assembly of key sarcomeric components to periodic myofibrils that then further mature during development. This requires transcriptional feedback mechanisms that may help to coordinate myofibril assembly and maturation states with the transcriptional program. To fuel the varying energy demands of muscles we also discuss the close mechanical interactions of myofibrils with mitochondria and nuclei to optimally support powerful or enduring muscle fibers.
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